Liu Xiang defeated world champion Jason Richardson to win the men's 110-meter hurdles at the rain-soaked Shanghai Diamond League meet on Saturday.
Jamaican runners topped their American rivals in the sprints. Asafa Powell held off Michael Rodgers to win the 100 meters, while Veronica Campbell-Brown beat Carmelita Jeter in the women's 200.
Liu and Richardson were even through the first seven hurdles before the Chinese star pulled away to win in 12.97 seconds, ripping off his shirt after crossing the finish line to a huge cheer from the crowd.
American David Oliver finished second in 13.13 and countryman Richardson was third in 13.16.
''Tonight, I executed very well,'' Liu said. ''I hope that I can keep my momentum, keep my form and pay attention to the details during the training so that I can perform well in the future.''
It was the first time Liu and Richardson met in a race since last year's world championships in Daegu, South Korea, where Liu tangled with Cuban Dayron Robles over the final hurdles. Robles crossed first but was disqualified after Liu appealed, elevating Richardson to first and Liu to second. Robles did not enter the Shanghai meet.
Liu, the 2004 Olympic champion and 2007 world champ, wasn't close to his best times of a few years ago but he was re-emerging as a favorite heading to the London Olympics.
He has two victories in his first two outdoor races of the year - he beat a weaker field in Japan two weeks ago. He also beat Robles by nearly a tenth of a second in an indoor 60-meter hurdles in February - their first meeting since the worlds last August.
Richardson said he was disappointed with the second half of the race, but he believes his fast times this early in the season bode well for London.
''I know that (Liu) is incredibly hard to beat here,'' he said. ''What I will say was surprising was to see an entire country get behind one athlete. I tip my hat to the Chinese culture. I wish we had a little bit more of that in America.''
Powell pulled away from the field after about 30 meters and held off a fast-closing Rodgers to win in 10.02 in wet, windy conditions.
Powell was coming off a second-place finish at the season-opening Diamond League event in Doha last week, when Justin Gatlin edged him by one hundredth of a second.
''Today I did technically well, so I'm happy,'' he said.
With the rain picking up, Campbell-Brown had a big lead coming off the curve in the women's 200, but Jeter pressed her down the final straight, just coming up short of the two-time Olympic 200 gold medalist.
''The more I win, the more confident I become, so it's good,'' Campbell-Brown said. ''This is my first 200-meter of the season and I have a lot of work to do. The way I feel in this one, I know that each one will get better.''
Americans had a better result in the men's 400 hurdles, with Angelo Taylor and Justin Gaymon finishing 1-2.
Taylor, the Olympic gold medalist in 2000 and 2008, is working his way back into form after an injured left foot last year disrupted his season. He said he feels confident less than three months away from London.
''This year, I'm being very, very cautious and being very aware of my body,'' he said. ''Mentally, I've been there and done that. I'm a two-time Olympic champion, so I know what it takes.''